Thursday, May 29, 2008 - 11:30 AM
545

Quantifying the impact of land-use on the biological condition of headwater streams

John F. Murphy1, Cynthia Davies1, John Davy-Bowker1, Pete Scarlett1, and Ralph T. Clarke2. (1) River Communities Research Group, Centre for Ecology & Hydrology, c/o Freshwater Biological Association, East Stoke, Wareham, BH20 6BB, England, (2) Centre for Conservation Ecology and Environmental Change, Bournemouth University, Christchurch House, Talbot Campus, Poole, United Kingdom

Existing attempts to relate catchment land-use to the ecological status of streams have been hampered by natural changes in land-use longitudinally along river systems and poor replication.  As part of the long-running Countryside Survey programme, a random-stratified sample of over 400 replicate headwaters across all British landscape types has been sampled in 1990, 1998 and 2007.  We sample the macroinvertebrate and aquatic plant communities as well as surveying hydromorphological features at each site.  We also map in detail the adjacent riparian vegetation and habitats as well as catchment land cover for each stream site.  Using this comprehensive dataset we found that there were weak relationships between land use at catchment and riparian scales, and stream ecological status, both nationally and within different landscape types.  We conclude that a more informative measure than % cover may be needed to describe the influence of parcels of habitat in catchments on stream condition.


Web Page: land-use, stream, macroinvertebrates